If you like live theater productions, book yourself some tickets for a show at Gloria-Theater. Check online for prices and times.
You'll be spoiled for sightseeing choice when visiting Bad Saeckingen. Gloria-Theater is a good place to kick off here, but there are plenty of other worthwhile spots to experience. Villa Berberich, Bad Saeckingen Church, and Frick Dinosaur Museum are not far from the arts and culture attraction and will fill in your day nicely.